[PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[abdoulaye berthe]

This avoids handling gpiochip remove error in device
remove handler.

Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>
---
 drivers/gpio/gpiolib.c      | 24 +++++++-----------------
 include/linux/gpio/driver.h |  2 +-
 2 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f48817d..4878980 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
  *
  * A gpio_chip with any GPIOs still requested may not be removed.
  */
-int gpiochip_remove(struct gpio_chip *chip)
+void gpiochip_remove(struct gpio_chip *chip)
 {
 	unsigned long	flags;
-	int		status = 0;
 	unsigned	id;
 
 	acpi_gpiochip_remove(chip);
@@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip)
 	of_gpiochip_remove(chip);
 
 	for (id = 0; id < chip->ngpio; id++) {
-		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
-			status = -EBUSY;
-			break;
-		}
-	}
-	if (status == 0) {
-		for (id = 0; id < chip->ngpio; id++)
-			chip->desc[id].chip = NULL;
-
-		list_del(&chip->list);
+		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
+			panic("gpiolib.c: gpiochip is still requested\n");
 	}
+	for (id = 0; id < chip->ngpio; id++)
+		chip->desc[id].chip = NULL;
 
+	list_del(&chip->list);
 	spin_unlock_irqrestore(&gpio_lock, flags);
-
-	if (status == 0)
-		gpiochip_unexport(chip);
-
-	return status;
+	gpiochip_unexport(chip);
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);
 
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 1827b43..72ed256 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -138,7 +138,7 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip,
 
 /* add/remove chips */
 extern int gpiochip_add(struct gpio_chip *chip);
-extern int __must_check gpiochip_remove(struct gpio_chip *chip);
+void gpiochip_remove(struct gpio_chip *chip);
 extern struct gpio_chip *gpiochip_find(void *data,
 			      int (*match)(struct gpio_chip *chip, void *data));
 
-- 
1.8.3.2

Re: [PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[Linus Walleij]

On Fri, May 23, 2014 at 7:03 PM, abdoulaye berthe <berthe.ab@gmail.com> wrote:

> This avoids handling gpiochip remove error in device
> remove handler.
>
> Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>

In general this is the right thing to do.

>         for (id = 0; id < chip->ngpio; id++) {
> -               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
> -                       status = -EBUSY;
> -                       break;
> -               }
> -       }
> -       if (status == 0) {
> -               for (id = 0; id < chip->ngpio; id++)
> -                       chip->desc[id].chip = NULL;
> -
> -               list_del(&chip->list);
> +               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
> +                       panic("gpiolib.c: gpiochip is still requested\n");

panic("gpio: removing gpiochip with gpios still requested\");
is more helpful.

But I want a patch that also removes *ALL* users of the return value
from this function in the *same* patch to avoid bisectability issues.

$ git grep gpiochip_remove

Then fix all of them or use coccinelle.

Yours,
Linus Walleij

[PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[abdoulaye berthe]

This avoids handling gpiochip remove error in device
remove handler.

Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>
---
 drivers/gpio/gpiolib.c      | 24 +++++++-----------------
 include/linux/gpio/driver.h |  2 +-
 2 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f48817d..022543f 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
  *
  * A gpio_chip with any GPIOs still requested may not be removed.
  */
-int gpiochip_remove(struct gpio_chip *chip)
+void gpiochip_remove(struct gpio_chip *chip)
 {
 	unsigned long	flags;
-	int		status = 0;
 	unsigned	id;
 
 	acpi_gpiochip_remove(chip);
@@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip)
 	of_gpiochip_remove(chip);
 
 	for (id = 0; id < chip->ngpio; id++) {
-		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
-			status = -EBUSY;
-			break;
-		}
-	}
-	if (status == 0) {
-		for (id = 0; id < chip->ngpio; id++)
-			chip->desc[id].chip = NULL;
-
-		list_del(&chip->list);
+		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
+			panic("gpio: removing gpiochip with gpios still requested\n");
 	}
+	for (id = 0; id < chip->ngpio; id++)
+		chip->desc[id].chip = NULL;
 
+	list_del(&chip->list);
 	spin_unlock_irqrestore(&gpio_lock, flags);
-
-	if (status == 0)
-		gpiochip_unexport(chip);
-
-	return status;
+	gpiochip_unexport(chip);
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);
 
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 1827b43..72ed256 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -138,7 +138,7 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip,
 
 /* add/remove chips */
 extern int gpiochip_add(struct gpio_chip *chip);
-extern int __must_check gpiochip_remove(struct gpio_chip *chip);
+void gpiochip_remove(struct gpio_chip *chip);
 extern struct gpio_chip *gpiochip_find(void *data,
 			      int (*match)(struct gpio_chip *chip, void *data));
 
-- 
1.8.3.2

Re: [PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[Stephen Rothwell]

[-- Attachment #1: Type: text/plain, Size: 418 bytes --]

Hi abdoulaye,

On Fri, 30 May 2014 00:32:02 +0200 abdoulaye berthe <berthe.ab@gmail.com> wrote:
>
> +		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
> +			panic("gpio: removing gpiochip with gpios still requested\n");

Someone else already commented that panic is probably overkill ... is
there no way to log this and continue?

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 836 bytes --]

[PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[abdoulaye berthe]

This avoids handling gpiochip remove error in device
remove handler.

Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>
---
 drivers/gpio/gpiolib.c      | 24 +++++++-----------------
 include/linux/gpio/driver.h |  2 +-
 2 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f48817d..4878980 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
  *
  * A gpio_chip with any GPIOs still requested may not be removed.
  */
-int gpiochip_remove(struct gpio_chip *chip)
+void gpiochip_remove(struct gpio_chip *chip)
 {
 	unsigned long	flags;
-	int		status = 0;
 	unsigned	id;
 
 	acpi_gpiochip_remove(chip);
@@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip)
 	of_gpiochip_remove(chip);
 
 	for (id = 0; id < chip->ngpio; id++) {
-		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
-			status = -EBUSY;
-			break;
-		}
-	}
-	if (status == 0) {
-		for (id = 0; id < chip->ngpio; id++)
-			chip->desc[id].chip = NULL;
-
-		list_del(&chip->list);
+		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
+			panic("gpiolib.c: gpiochip is still requested\n");
 	}
+	for (id = 0; id < chip->ngpio; id++)
+		chip->desc[id].chip = NULL;
 
+	list_del(&chip->list);
 	spin_unlock_irqrestore(&gpio_lock, flags);
-
-	if (status == 0)
-		gpiochip_unexport(chip);
-
-	return status;
+	gpiochip_unexport(chip);
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);
 
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 1827b43..72ed256 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -138,7 +138,7 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip,
 
 /* add/remove chips */
 extern int gpiochip_add(struct gpio_chip *chip);
-extern int __must_check gpiochip_remove(struct gpio_chip *chip);
+void gpiochip_remove(struct gpio_chip *chip);
 extern struct gpio_chip *gpiochip_find(void *data,
 			      int (*match)(struct gpio_chip *chip, void *data));
 
-- 
1.8.3.2

Re: [PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[abdoulaye berthe]

If this step is ok I will continue by updating the codes that use it.

On Fri, May 23, 2014 at 7:12 PM, abdoulaye berthe <berthe.ab@gmail.com> wrote:
> This avoids handling gpiochip remove error in device
> remove handler.
>
> Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>
> ---
>  drivers/gpio/gpiolib.c      | 24 +++++++-----------------
>  include/linux/gpio/driver.h |  2 +-
>  2 files changed, 8 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index f48817d..4878980 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
>   *
>   * A gpio_chip with any GPIOs still requested may not be removed.
>   */
> -int gpiochip_remove(struct gpio_chip *chip)
> +void gpiochip_remove(struct gpio_chip *chip)
>  {
>         unsigned long   flags;
> -       int             status = 0;
>         unsigned        id;
>
>         acpi_gpiochip_remove(chip);
> @@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip)
>         of_gpiochip_remove(chip);
>
>         for (id = 0; id < chip->ngpio; id++) {
> -               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
> -                       status = -EBUSY;
> -                       break;
> -               }
> -       }
> -       if (status == 0) {
> -               for (id = 0; id < chip->ngpio; id++)
> -                       chip->desc[id].chip = NULL;
> -
> -               list_del(&chip->list);
> +               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
> +                       panic("gpiolib.c: gpiochip is still requested\n");
>         }
> +       for (id = 0; id < chip->ngpio; id++)
> +               chip->desc[id].chip = NULL;
>
> +       list_del(&chip->list);
>         spin_unlock_irqrestore(&gpio_lock, flags);
> -
> -       if (status == 0)
> -               gpiochip_unexport(chip);
> -
> -       return status;
> +       gpiochip_unexport(chip);
>  }
>  EXPORT_SYMBOL_GPL(gpiochip_remove);
>
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index 1827b43..72ed256 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -138,7 +138,7 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip,
>
>  /* add/remove chips */
>  extern int gpiochip_add(struct gpio_chip *chip);
> -extern int __must_check gpiochip_remove(struct gpio_chip *chip);
> +void gpiochip_remove(struct gpio_chip *chip);
>  extern struct gpio_chip *gpiochip_find(void *data,
>                               int (*match)(struct gpio_chip *chip, void *data));
>
> --
> 1.8.3.2
>

Re: [PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[Alexandre Courbot]

On Sat, May 24, 2014 at 2:12 AM, abdoulaye berthe <berthe.ab@gmail.com> wrote:
> This avoids handling gpiochip remove error in device
> remove handler.

Be aware that at the moment many callers of gpiochip_remove() read its
return value. So applying your patch as-is would break compilation.

This patch should therefore be the last of a series that first
modifies all callers of gpiochip_remove() to ignore its return value,
then neutralizes the function itself.

I am not sure whether the world would really be a better place after
this though. Callers that don't need the return value of
gpiochip_remove() can simply ignore it...

>
> Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>
> ---
>  drivers/gpio/gpiolib.c      | 24 +++++++-----------------
>  include/linux/gpio/driver.h |  2 +-
>  2 files changed, 8 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index f48817d..4878980 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
>   *
>   * A gpio_chip with any GPIOs still requested may not be removed.
>   */
> -int gpiochip_remove(struct gpio_chip *chip)
> +void gpiochip_remove(struct gpio_chip *chip)
>  {
>         unsigned long   flags;
> -       int             status = 0;
>         unsigned        id;
>
>         acpi_gpiochip_remove(chip);
> @@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip)
>         of_gpiochip_remove(chip);
>
>         for (id = 0; id < chip->ngpio; id++) {
> -               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
> -                       status = -EBUSY;
> -                       break;
> -               }
> -       }
> -       if (status == 0) {
> -               for (id = 0; id < chip->ngpio; id++)
> -                       chip->desc[id].chip = NULL;
> -
> -               list_del(&chip->list);
> +               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
> +                       panic("gpiolib.c: gpiochip is still requested\n");

panic() sounds a little harsh here. Maybe a dev_err() would be enough?

>         }
> +       for (id = 0; id < chip->ngpio; id++)
> +               chip->desc[id].chip = NULL;
>
> +       list_del(&chip->list);
>         spin_unlock_irqrestore(&gpio_lock, flags);
> -
> -       if (status == 0)
> -               gpiochip_unexport(chip);
> -
> -       return status;
> +       gpiochip_unexport(chip);
>  }
>  EXPORT_SYMBOL_GPL(gpiochip_remove);
>
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index 1827b43..72ed256 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -138,7 +138,7 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip,
>
>  /* add/remove chips */
>  extern int gpiochip_add(struct gpio_chip *chip);
> -extern int __must_check gpiochip_remove(struct gpio_chip *chip);
> +void gpiochip_remove(struct gpio_chip *chip);

"extern" should be preserved here for style consistency.

Re: [PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[abdoulaye berthe]

Well, ignoring the return value as it is done in gpio-bt8xx makes the
compiler complain and display a warning message. The problem with
false warning is that it might distract you. I think that the patch
will makes things consistent once completed
Thanks a lot for the review.

On Sun, May 25, 2014 at 9:46 AM, Alexandre Courbot <gnurou@gmail.com> wrote:
> On Sat, May 24, 2014 at 2:12 AM, abdoulaye berthe <berthe.ab@gmail.com> wrote:
>> This avoids handling gpiochip remove error in device
>> remove handler.
>
> Be aware that at the moment many callers of gpiochip_remove() read its
> return value. So applying your patch as-is would break compilation.
>
> This patch should therefore be the last of a series that first
> modifies all callers of gpiochip_remove() to ignore its return value,
> then neutralizes the function itself.
>
> I am not sure whether the world would really be a better place after
> this though. Callers that don't need the return value of
> gpiochip_remove() can simply ignore it...
>
>>
>> Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>
>> ---
>>  drivers/gpio/gpiolib.c      | 24 +++++++-----------------
>>  include/linux/gpio/driver.h |  2 +-
>>  2 files changed, 8 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
>> index f48817d..4878980 100644
>> --- a/drivers/gpio/gpiolib.c
>> +++ b/drivers/gpio/gpiolib.c
>> @@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
>>   *
>>   * A gpio_chip with any GPIOs still requested may not be removed.
>>   */
>> -int gpiochip_remove(struct gpio_chip *chip)
>> +void gpiochip_remove(struct gpio_chip *chip)
>>  {
>>         unsigned long   flags;
>> -       int             status = 0;
>>         unsigned        id;
>>
>>         acpi_gpiochip_remove(chip);
>> @@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip)
>>         of_gpiochip_remove(chip);
>>
>>         for (id = 0; id < chip->ngpio; id++) {
>> -               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
>> -                       status = -EBUSY;
>> -                       break;
>> -               }
>> -       }
>> -       if (status == 0) {
>> -               for (id = 0; id < chip->ngpio; id++)
>> -                       chip->desc[id].chip = NULL;
>> -
>> -               list_del(&chip->list);
>> +               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
>> +                       panic("gpiolib.c: gpiochip is still requested\n");
>
> panic() sounds a little harsh here. Maybe a dev_err() would be enough?
>
>>         }
>> +       for (id = 0; id < chip->ngpio; id++)
>> +               chip->desc[id].chip = NULL;
>>
>> +       list_del(&chip->list);
>>         spin_unlock_irqrestore(&gpio_lock, flags);
>> -
>> -       if (status == 0)
>> -               gpiochip_unexport(chip);
>> -
>> -       return status;
>> +       gpiochip_unexport(chip);
>>  }
>>  EXPORT_SYMBOL_GPL(gpiochip_remove);
>>
>> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
>> index 1827b43..72ed256 100644
>> --- a/include/linux/gpio/driver.h
>> +++ b/include/linux/gpio/driver.h
>> @@ -138,7 +138,7 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip,
>>
>>  /* add/remove chips */
>>  extern int gpiochip_add(struct gpio_chip *chip);
>> -extern int __must_check gpiochip_remove(struct gpio_chip *chip);
>> +void gpiochip_remove(struct gpio_chip *chip);
>
> "extern" should be preserved here for style consistency.

Re: [PATCH] gpio: gpiolib: set gpiochip_remove retval to void

[Alexandre Courbot]

On Mon, May 26, 2014 at 1:40 AM, abdoulaye berthe <berthe.ab@gmail.com> wrote:
> Well, ignoring the return value as it is done in gpio-bt8xx makes the
> compiler complain and display a warning message. The problem with
> false warning is that it might distract you.

Isn't the warning due to the __must_check in the function's
declaration? If so just removing it might do the trick...

> I think that the patch
> will makes things consistent once completed

Yeah fundamentally speaking I am not against this patch - I just
wonder if it is worth going through all the call sites and changing
them. Also we cannot exclude that a few users actually make something
meaningful with the return value (don't know what that would be
though).

> Thanks a lot for the review.
>
> On Sun, May 25, 2014 at 9:46 AM, Alexandre Courbot <gnurou@gmail.com> wrote:
>> On Sat, May 24, 2014 at 2:12 AM, abdoulaye berthe <berthe.ab@gmail.com> wrote:
>>> This avoids handling gpiochip remove error in device
>>> remove handler.
>>
>> Be aware that at the moment many callers of gpiochip_remove() read its
>> return value. So applying your patch as-is would break compilation.
>>
>> This patch should therefore be the last of a series that first
>> modifies all callers of gpiochip_remove() to ignore its return value,
>> then neutralizes the function itself.
>>
>> I am not sure whether the world would really be a better place after
>> this though. Callers that don't need the return value of
>> gpiochip_remove() can simply ignore it...
>>
>>>
>>> Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>
>>> ---
>>>  drivers/gpio/gpiolib.c      | 24 +++++++-----------------
>>>  include/linux/gpio/driver.h |  2 +-
>>>  2 files changed, 8 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
>>> index f48817d..4878980 100644
>>> --- a/drivers/gpio/gpiolib.c
>>> +++ b/drivers/gpio/gpiolib.c
>>> @@ -1263,10 +1263,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
>>>   *
>>>   * A gpio_chip with any GPIOs still requested may not be removed.
>>>   */
>>> -int gpiochip_remove(struct gpio_chip *chip)
>>> +void gpiochip_remove(struct gpio_chip *chip)
>>>  {
>>>         unsigned long   flags;
>>> -       int             status = 0;
>>>         unsigned        id;
>>>
>>>         acpi_gpiochip_remove(chip);
>>> @@ -1278,24 +1277,15 @@ int gpiochip_remove(struct gpio_chip *chip)
>>>         of_gpiochip_remove(chip);
>>>
>>>         for (id = 0; id < chip->ngpio; id++) {
>>> -               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
>>> -                       status = -EBUSY;
>>> -                       break;
>>> -               }
>>> -       }
>>> -       if (status == 0) {
>>> -               for (id = 0; id < chip->ngpio; id++)
>>> -                       chip->desc[id].chip = NULL;
>>> -
>>> -               list_del(&chip->list);
>>> +               if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
>>> +                       panic("gpiolib.c: gpiochip is still requested\n");
>>
>> panic() sounds a little harsh here. Maybe a dev_err() would be enough?
>>
>>>         }
>>> +       for (id = 0; id < chip->ngpio; id++)
>>> +               chip->desc[id].chip = NULL;
>>>
>>> +       list_del(&chip->list);
>>>         spin_unlock_irqrestore(&gpio_lock, flags);
>>> -
>>> -       if (status == 0)
>>> -               gpiochip_unexport(chip);
>>> -
>>> -       return status;
>>> +       gpiochip_unexport(chip);
>>>  }
>>>  EXPORT_SYMBOL_GPL(gpiochip_remove);
>>>
>>> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
>>> index 1827b43..72ed256 100644
>>> --- a/include/linux/gpio/driver.h
>>> +++ b/include/linux/gpio/driver.h
>>> @@ -138,7 +138,7 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip,
>>>
>>>  /* add/remove chips */
>>>  extern int gpiochip_add(struct gpio_chip *chip);
>>> -extern int __must_check gpiochip_remove(struct gpio_chip *chip);
>>> +void gpiochip_remove(struct gpio_chip *chip);
>>
>> "extern" should be preserved here for style consistency.